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Multiple approaches for instrumentation of the upper cervical spine have evolved to treat atlantoaxial instability which, until the 20th century, was largely considered to be inoperable and managed nonsurgically with immobilization. Surgeons set out to provide safe and effective approaches in a clearly dangerous and technically complex anatomic region. It is important to provide a historical analysis of the evolution of techniques that have shaped C1-C2 instrumentation, and how the diligent efforts of surgeons to improve the biomechanical stability and fusion rates of their constructs eventually led to the prevailing Harms technique. This technique is explored by describing its surgical steps, alternative techniques, and associated outcomes. For successful instrumentation of the atlantoaxial joint, a comprehensive understanding of spinal biomechanics, surgical techniques, and anatomic variations is imperative for surgeons to develop a tailored plan for each patient's individual pathology and anatomy.
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Articulación Atlantoaxoidea , Inestabilidad de la Articulación , Fusión Vertebral , Humanos , Fusión Vertebral/métodos , Tornillos Óseos , Vértebras Cervicales/cirugía , Articulación Atlantoaxoidea/cirugía , Inestabilidad de la Articulación/cirugíaRESUMEN
PURPOSE: Magnetic resonance imaging (MRI) is routinely used to evaluate spine pathology; however, standard imaging findings weakly correlate to low back pain. Abnormal disc mechanical function is implicated as a cause of back pain but is not assessed using standard clinical MRI. Our objective was to utilize our established MRI protocol for measuring disc function to quantify disc mechanical function in a healthy cohort. METHODS: We recruited young, asymptomatic volunteers (6 male/6 female; age 18-30 years; BMI < 30) and used MRI to determine how diurnal deformations in disc height, volume, and perimeter were affected by spinal level, disc region, MRI biomarkers of disc health (T2, T1rho), and Pfirrmann grade. RESULTS: Lumbar discs deformed by a mean of -6.1% (95% CI: -7.6%, -4.7%) to -8.0% (CI: -10.6%, -5.4%) in height and -5.4% (CI: -7.6%, -3.3%) to -8.5% (CI: -11.0%, -6.0%) in volume from AM to PM across spinal levels. Regional deformations were more uniform in cranial lumbar levels and concentrated posteriorly in the caudal levels, reaching a maximum of 13.1% at L5-S1 (CI:-16.1%, -10.2%). T2 and T1rho relaxation times were greatest in the nucleus and varied circumferentially within the annulus. T2 relaxation times were greatest at the most cranial spinal levels and decreased caudally. In this young healthy cohort, we identified a weak association between nucleus T2 and the diurnal change in the perimeter. CONCLUSIONS: Spinal level is a key factor in determining regional disc deformations. Interestingly, deformations were concentrated in the posterior regions of caudal discs where disc herniation is most prevalent.
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Degeneración del Disco Intervertebral , Desplazamiento del Disco Intervertebral , Disco Intervertebral , Dolor de la Región Lumbar , Adolescente , Adulto , Femenino , Humanos , Disco Intervertebral/diagnóstico por imagen , Disco Intervertebral/patología , Degeneración del Disco Intervertebral/patología , Desplazamiento del Disco Intervertebral/complicaciones , Dolor de la Región Lumbar/etiología , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/patología , Imagen por Resonancia Magnética/métodos , Masculino , Adulto JovenRESUMEN
OBJECTIVE: In patients with metastatic spinal disease (MSD), interhospital transfer can potentially impact clinical outcomes as the possible benefits of transferring a patient to a higher level of care must be weighed against the negative effects associated with potential delays in treatment. While the association of clinical outcomes and transfer status has been examined in other specialties, the relationship between transfer status, complications, and risk of mortality in patients with MSD has yet to be explored. The purpose of this study was to examine the impact of transfer status on in-hospital mortality and clinical outcomes in patients diagnosed with MSD. METHODS: The National (Nationwide) Inpatient Sample (NIS) database was retrospectively queried for adult patients diagnosed with vertebral pathological fracture and/or spinal cord compression in the setting of metastatic disease between 2012 and 2014. Demographics, baseline characteristics (e.g., metastatic spinal cord compression [MSCC] and paralysis), comorbidities, type of intervention, and relevant patient outcomes were controlled in a multivariable logistic regression model to analyze the association of transfer status with patient outcomes. RESULTS: Within the 10,360 patients meeting the inclusion and exclusion criteria, higher rates of MSCC (50.2% vs 35.9%, p < 0.001) and paralysis (17.3% vs 8.4%, p < 0.001) were observed in patients transferred between hospitals compared to those directly admitted. In univariable analysis, a higher percentage of transferred patients underwent surgical intervention (p < 0.001) when compared with directly admitted patients. After controlling for significant covariates and surgical intervention, transferred patients were more likely to develop in-hospital complications (OR 1.34, 95% CI 1.18-1.52, p < 0.001), experience prolonged length of stay (OR 1.33, 95% CI 1.16-1.52, p < 0.001), and have a discharge disposition other than home (OR 1.70, 95% CI 1.46-1.98, p < 0.001), with no significant difference in inpatient mortality rates. CONCLUSIONS: Patients with MSD who were transferred between hospitals demonstrated more severe clinical presentations and higher rates of inpatient complications compared to directly admitted patients, despite demonstrating no difference in in-hospital mortality rates.
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Compresión de la Médula Espinal , Neoplasias de la Columna Vertebral , Adulto , Hospitalización , Humanos , Pacientes Internos , Tiempo de Internación , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Estados Unidos/epidemiologíaRESUMEN
Care for patients during COVID-19 poses challenges that require the protection of staff with recommendations that health care workers wear at minimum, an N95 mask or equivalent while performing an aerosol-generating procedure with a face shield. The United States faces shortages of personal protective equipment (PPE), and surgeons who use loupes and headlights have difficulty using these in conjunction with face shields. Most arthroplasty surgeons use surgical helmet systems, but in the current pandemic, many hospitals have delayed elective arthroplasty surgeries and the helmet systems are going unused. As a result, the authors have begun retrofitting these arthroplasty helmets to serve as PPE. The purpose of this article is to outline the conception, design, donning technique, and safety testing of these arthroplasty helmets being repurposed as PPE.
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Betacoronavirus , Infecciones por Coronavirus/prevención & control , Dispositivos de Protección de la Cabeza , Pandemias/prevención & control , Equipo de Protección Personal , Neumonía Viral/prevención & control , Impresión Tridimensional , Centros Médicos Académicos , Aerosoles , COVID-19 , Infecciones por Coronavirus/transmisión , Personal de Salud , Humanos , Equipo de Protección Personal/normas , Neumonía Viral/transmisión , SARS-CoV-2 , Estados UnidosRESUMEN
Importance: Board certification can have broad implications for candidates' career trajectories, and prior research has found sociodemographic disparities in pass rates. Barriers in the format and administration of the oral board examinations may disproportionately affect certain candidates. Objective: To characterize oral certifying examination policies and practices of the 16 Accreditation Council for Graduate Medical Education (ACGME)-accredited specialties that require oral examinations. Design, Setting, and Participants: This cross-sectional study was conducted from March 1 to April 15, 2023, using data on oral examination practices and policies (examination format, dates, and setting; lactation accommodations; and accommodations for military deployment, family emergency, or medical leave) as well as the gender composition of the specialties' boards of directors obtained from websites, telephone calls and email correspondence with certifying specialists. The percentages of female residents and residents of racial and ethnic backgrounds who are historically underrepresented in medicine (URM) in each specialty as of December 31, 2021, were obtained from the Graduate Medical Education 2021 to 2022 report. Main Outcome and Measures: For each specialty, accommodation scores were measured by a modified objective scoring system (score range: 1-13, with higher scores indicating more accommodations). Poisson regression was used to assess the association between accommodation score and the diversity of residents in that specialty, as measured by the percentages of female and URM residents. Linear regression was used to assess whether gender diversity of a specialty's board of directors was associated with accommodation scores. Results: Included in the analysis were 16 specialties with a total of 46 027 residents (26 533 males [57.6%]) and 233 members of boards of directors (152 males [65.2%]). The mean (SD) total accommodation score was 8.28 (3.79), and the median (IQR) score was 9.25 (5.00-12.00). No association was found between test accommodation score and the percentage of female or URM residents. However, for each 1-point increase in the test accommodation score, the relative risk that a resident was female was 1.05 (95% CI, 0.96-1.16), and the relative risk that an individual was a URM resident was 1.04 (95% CI, 1.00-1.07). An association was found between the percentage of female board members and the accommodation score: for each 10% increase in the percentage of board members who were female, the accommodation score increased by 1.20 points (95% CI, 0.23-2.16 points; P = .03). Conclusions and Relevance: This cross-sectional study found considerable variability in oral board examination accommodations among ACGME-accredited specialties, highlighting opportunities for improvement and standardization. Promoting diversity in leadership bodies may lead to greater accommodations for examinees in extenuating circumstances.
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Certificación , Humanos , Estudios Transversales , Femenino , Masculino , Certificación/estadística & datos numéricos , Estados Unidos , Consejos de Especialidades/estadística & datos numéricos , Evaluación Educacional/estadística & datos numéricos , Evaluación Educacional/métodos , Educación de Postgrado en Medicina/estadística & datos numéricos , Medicina/estadística & datos numéricos , AdultoRESUMEN
INTRODUCTION: In recent years, healthcare institutions and regulatory bodies have enacted cost transparency mandates for routine interventions such as total hip arthroplasty and total knee arthroplasty. However, disclosure rates remain low. This study examined the effect of financial characteristics of hospitals and the socioeconomic status of patients on price disclosure. METHODS: Hospitals conducting total hip arthroplasty/total knee arthroplasty, their quality ratings, and procedural volumes were identified using the Leapfrog Hospital Survey and linked to procedure-specific prices. Financial performance and the Area Deprivation Index (ADI) were used to correlate disclosure rates with hospital and patient characteristics. Hospital financial, operational, and patient summary statistics were compared by price-disclosure status using two-sample t -tests for continuous variables and Pearson chi-square test for categorical variables. The association between total joint arthroplasty price disclosure and hospital ADI was further evaluated using modified Poisson regression. RESULTS: A total of 1,425 hospitals certified by the Centers for Medicare & Medicaid Services were identified in the United States. 50.5% (n = 721) of hospitals had no published payer-specific price information. Hospitals in an area of higher socioeconomic disadvantage were more likely to disclose prices of total joint arthroplasty (incidence rate ratio = 0.966, 95% CI: 0.937 to 0.995, P = 0.024). Hospitals that were considered monopolies or were for-profit were less likely to disclose prices (IRR = 1.15, 95% CI: 1.030 to 1.280, P = 0.01; IRR = 1.256, 95% CI: 0.986 to 1.526, P = 0.038, respectively). When accounting for both ADI and monopoly status, hospitals with patients who had a higher ADI were more likely to disclose costs for a total joint arthroplasty, whereas for-profit hospitals or hospitals considered monopolies in their HSA were less likely to disclose prices. DISCUSSION: For nonmonopoly hospitals, a higher ADI correlated with a higher likelihood of price disclosure. However, for monopoly hospitals, there was no significant association between ADI and price disclosure. LEVEL OF EVIDENCE: II.
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Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Humanos , Anciano , Estados Unidos , Revelación , Disparidades Socioeconómicas en Salud , Medicare , HospitalesRESUMEN
BACKGROUND: In the United States, women comprise 16% of orthopaedic surgery residents, 4% of fellows, and 6% of practicing orthopaedic surgeons. The underrepresentation of women in surgical subspecialties may be because of lack of early exposure to female mentors. Conference speaker roles are important for visibility. This study aims to evaluate the representation of women in speaker roles and responsibilities at the American Academy of Orthopaedic Surgeons (AAOS) meetings over time. METHODS: The names of speakers and session titles at the annual AAOS meetings were obtained from conference programs for the years 2009, 2014, and 2019. Each speaker was classified based on sex and role. Sessions discussing scientific or surgical topics were classified as technical and those that did not were classified as nontechnical. Descriptive statistics are provided, as well as individual-year odds ratios (ORs) and confidence intervals (CIs) examining sex versus technical session status and sex versus speaker role; combined results controlling for year are calculated using the Cochran-Mantel-Haenszel method. RESULTS: Overall, 3,980 speaking sessions were analyzed; 6.8% of speaking sessions were assigned to women. Women were more likely than men to participate in nontechnical speaking roles (OR 3.85; 95% CI, 2.79 to 4.78). Among talks given by women, the percentage that were nontechnical increased (25.5% in 2009, 24.3% in 2014, and 44.1% in 2019). Among moderator roles, the percentage assigned to women increased (4.5% in 2009, 6.0% in 2014, 14.5% in 2019). DISCUSSION: Our findings demonstrate an increase in female speakers at AAOS meetings from 2009 to 2019. The percentage of female moderators and nontechnical sessions given by women increased since 2009. A need for a shift in the distribution of speaker role exists, which promotes inclusivity and prevents professional marginalization. Representation of women as role models increases visibility and may address the leaky pipeline phenomenon and paucity of women in orthopaedics.
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Cirujanos Ortopédicos , Ortopedia , Masculino , Humanos , Estados Unidos , Femenino , Sociedades MédicasRESUMEN
The prone lateral transpsoas approach for lumbar interbody fusion and posterior instrumentation enables a large surface area implant without disruption of the posterior spine musculature from a single position.1,2 The addition of virtual live fluoroscopy instrument tracking navigation to surgery provides multiple benefits, including a reduction in patient and surgeon radiation exposure, highly accurate and dynamic spatial tool localization, and flexible equipment and patient positioning.3,4 Here, we highlight the use of virtual live fluoroscopy in prone lateral spine surgery. A 75-year-old man presented with prior L3-L5 fusion and progressive lower extremity pain and weakness. Using the described techniques, the patient underwent a lateral retroperitoneal interbody fusion and posterior instrumentation at L2-L3. The operation proceeded without complication, and the patient reported improved ambulation at 6-week follow-up. The prone lateral transpsoas approach and minimally invasive posterior instrumentation for lumbar interbody fusion permits effective fusion without significant posterior muscle disruption from a single position. The integration of virtual live fluoroscopy enables real-time instrument tracking throughout the minimally invasive case, with reductions in patient and surgeon radiation exposure. Video 1 depicts the use and benefits of this technology in lateral spine surgery. Compared with computed tomography-guided navigation, virtual live fluoroscopy technology enables rapid remapping to iatrogenic anatomic changes for more fluid progression through the operation.5 Virtual live fluoroscopy instrument tracking is a valuable tool that increases the safety and efficiency of single-position lateral spine surgery.
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Procedimientos Quirúrgicos Mínimamente Invasivos , Fusión Vertebral , Masculino , Humanos , Anciano , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Fusión Vertebral/métodos , Fluoroscopía , Tomografía Computarizada por Rayos XRESUMEN
INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) is among the most common spine procedures. Adjacent segment disease (ASD), characterized by degenerative disease at an adjacent spinal level to a prior fusion, is a well-recognized and significant sequela following ACDF. Adjacent segment ACDF may be considered after the failure of non-surgical options for patients with symptomatic ASD. This study aimed to assess the incidence of dysphagia and other complications as well as radiographic outcomes in adult patients who have undergone ACDF with an integrated interbody spacer device for symptomatic ASD. METHODS: This was a retrospective review of patients who underwent ACDF for symptomatic ASD with commercially available integrated interbody spacers by three spine surgeons at an academic institution from March 2018 to April 2022. Demographic, radiographic, and postoperative data were collected, including dysphagia, device-related complications, and the need for revision surgery. RESULTS: There were 48 patients (26 male, 22 female) who met inclusion criteria (mean age 59.7 years, mean body mass index 19.5 kg/m2) who underwent ACDF for symptomatic ASD (1one-level, n = 44; 2-level, n = 4). Overall, 12 patients (25%) experienced dysphagia postoperatively before the first follow-up appointment. Nine of 44 (20.4%) of 1-level ACDF patients experienced dysphagia, and 3 of 4 (75%) of 2-level ACDF patients experienced dysphagia. Three patients had severe dysphagia which prompted an otolaryngology referral. Two of those patients remained symptomatic at 6 weeks postoperatively. Of 43 patients with prior plate cage systems, none required hardware removal at the time of surgery. Preoperative global and segmental lordosis were 9.07° ± 8.36° (P = 0.22) and 3.58° ± 4.57° (P = 0.14), respectively. At 6 weeks postoperatively, global and segmental lordosis were 11.44° ± 9.06° (P = 0.54) and 5.11° ± 4.44° (P = 0.44), respectively. This constitutes a change of +2.37° and +1.53° in global and segmental lordosis, respectively. The mean anterior disc height change between preoperative and immediate postoperative time points was 6.3 ± 3.1 mm. Between the immediate postoperative and 6-week postoperative time points, the mean anterior disc height change was -1.5 ± 2.7 mm. Between the immediate postoperative and 3-month postoperative time points, the mean anterior disc height change was -3.7 ± 5.0 mm. The posterior disc height changes at the same time points were 2.5 ± 1.7 mm, -0.4 ± 1.8. and -0.5 ± 1.4 mm, respectively. This fusion rate was 50% and 70% at 6 months and 1 year post-surgery, respectively. CONCLUSIONS: ACDF with integrated spacer is a viable alternative to traditional plate-cage systems for symptomatic ASD. An advantage over traditional plate-cage systems is that the removal of prior instrumentation is not needed in order to place implants. Based on a review of the literature, these standalone systems allowed for a shorter operative time and had less incidence of dysphagia than plate-cage systems for ASD after ACDF. The different standalone and plate-cage systems used in treating ASD after ACDF surgeries should be compared in prospective studies.
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Trastornos de Deglución , Lordosis , Fusión Vertebral , Adulto , Humanos , Masculino , Femenino , Persona de Mediana Edad , Resultado del Tratamiento , Lordosis/cirugía , Trastornos de Deglución/etiología , Trastornos de Deglución/complicaciones , Estudios Prospectivos , Discectomía/métodos , Estudios Retrospectivos , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Fusión Vertebral/métodos , Estudios de SeguimientoRESUMEN
Dr. Ruth Jackson, born in 1902, was the first female spine surgeon on record. Her story of remarkable resilience and sacrifice is even more relevant given the stark gender disparities in orthopedic surgery and neurosurgery that remain today. Dr. Jackson entered the field during the Great Depression and overcame significant barriers at each step along the process. In 1937, she became the first woman to pass the American Board of Orthopedic Surgery examination and join the American Academy of Orthopedic Surgeons as a full member. Her work in the cervical spine led to a notable lecture record and the publication of several articles, as well as a book, The Cervical Syndrome, in which she discussed the anatomy, etiology, and treatment of cervical pathologies. Additionally, Dr. Jackson developed the Jackson CerviPillo, a neck support that is still in use today. She left a legacy that continues to resonate through the work of the Ruth Jackson Orthopedic Society, which supports women at all levels of practice and training. From the story of Dr. Jackson's life, we can appreciate her single-minded determination that blazed a path for women in spine surgery, as well as consider the progress that remains to be made.
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In this video, the authors highlight the operative treatment of a 55-year-old man with chronic osteomyelitis discitis. The operation entailed a minimally invasive lateral retroperitoneal transpsoas approach for L3 and L4 corpectomies, L2-5 interbody fusion, and L2-5 minimally invasive posterior instrumentation. The operation proceeded in two stages, beginning in the lateral position with corpectomy of the L3 and L4 vertebral bodies and placement of a corpectomy cage. After closure of this access wound, the patient was turned to a prone position for the posterior element of the operation. Posterior instrumentation was placed with pedicle screws at L2 and L5. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2210.
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BACKGROUND CONTEXT: Preoperative optimization of medical comorbidities prior to spinal surgery is becoming an increasingly important intervention in decreasing postoperative complications and ensuring a satisfactory postoperative course. The treatment of preoperative anemia is based on guidelines made by the American College of Cardiology (ACC), which recommends packed red blood cell transfusion when hematocrit is less than 21% in patients without cardiovascular disease and 24% in patients with cardiovascular disease. The literature has yet to quantify the risk profile associated with preoperative pRBC transfusion. PURPOSE: To determine the incidence of complications following preoperative pRBC transfusion in a cohort of patients undergoing spine surgery. STUDY DESIGN: Retrospective review of a national surgical database. PATIENT SAMPLE: The national surgical quality improvement program database OUTCOME NEASURES: Postoperative physiologic complications after a preoperative transfusion. Complications were defined as the occurrence of any DVT, PE, stroke, cardiac arrest, myocardial infarction, longer length of stay, need for mechanical ventilation greater than 48â¯h, surgical site infections, sepsis, urinary tract infections, pneumonia, or higher 30-day mortality. METHODS: The national surgical quality improvement program database was queried, and patients were included if they had any type of spine surgery and had a preoperative transfusion. RESULTS: Preoperative pRBC transfusion was found to be protective against complications when the hematocrit was less than 20% and associated with more complications when the hematocrit was higher than 20%. In patients with a hematocrit higher than 20%, pRBC transfusion was associated with longer lengths of stay, and higher rates of ventilator dependency greater than 48â¯h, pneumonia, and 30-day mortality. CONCLUSION: This is the first study to identify an inflection point in determining when a preoperative pRBC transfusion may be protective or may contribute to complications. Further studies are needed to be conducted to stratify by the prevalence of cardiovascular disease.
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Transfusión de Eritrocitos/tendencias , Procedimientos Neuroquirúrgicos/tendencias , Complicaciones Posoperatorias/sangre , Cuidados Preoperatorios/tendencias , Mejoramiento de la Calidad/tendencias , Enfermedades de la Columna Vertebral/sangre , Adulto , Anciano , Bases de Datos Factuales/tendencias , Transfusión de Eritrocitos/métodos , Femenino , Hematócrito/tendencias , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos/efectos adversos , Complicaciones Posoperatorias/etiología , Valor Predictivo de las Pruebas , Cuidados Preoperatorios/métodos , Estudios Retrospectivos , Enfermedades de la Columna Vertebral/cirugíaRESUMEN
BACKGROUND CONTEXT: Facility volume has been correlated with survival in many cancers. This relationship has not been established in primary malignant bone tumors of the vertebral column (BTVC). PURPOSE: To investigate whether facility patient volume is associated with overall survival in patients with primary malignant BTVCs. STUDY DESIGN: Retrospective comparative cohort. PATIENT SAMPLE: Adult patients with chordomas, chondrosarcomas, or osteosarcomas of the mobile spine. OUTCOME MEASURES: Five-year survival. METHODS: We retrospectively analyzed 733 patients with primary malignant BTVCs in the national cancer database from 2004 through 2015. Univariate and multivariate analyses were used to correlate specific outcome measures with facility volume. Volume was stratified based on cumulative martingale residuals to determine the inflection point of negative to positive impact on survival based on the patient cohort. Long-term survival was compared between patients treated at high and low volume using the Kaplan-Meier method. Only patients with malignant primary tumors were considered eligible for inclusion; patients with incomplete treatment data or benign tumors were excluded. RESULTS: Patients treated at high-volume centers (HVCs) were younger (p=.0003) and more likely to be insured (p<.0001). There were no significant differences in tumor characteristics. Patients treated at high-volume facilities had improved 5-year survival of 71% versus 58% at low-volume centers (p<.0001). Patients treated at HVCs were more likely to receive surgical treatment (91% vs. 80%, p<.0001); if surgery was performed, they were more likely to undergo an en bloc resection (48% vs. 30%, p<.0001). However, there were no differences in margin status or utilization of radiotherapy or chemotherapy between HVCs and low-volume centers. In a multivariate analysis, facility volume was independently associated with improved survival overall (HR 0.75 [0.58-0.97], p=.03). CONCLUSIONS: Primary malignant BTVCs are rare, even for HVCs. Despite this, patient survival was significantly improved when treatment was performed at HVCs.
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Cordoma , Neoplasias de la Columna Vertebral , Estudios de Cohortes , Humanos , Estudios Retrospectivos , Neoplasias de la Columna Vertebral/cirugía , Columna Vertebral , Resultado del TratamientoRESUMEN
Low back pain is a significant socioeconomic burden in the United States and lumbar intervertebral disc degeneration is frequently implicated as a cause. The discs play an important mechanical role in the spine, yet the relationship between disc function and back pain is poorly defined. The objective of this work was to develop a technique using magnetic resonance imaging (MRI) and three-dimensional modeling to measure in vivo disc deformations. Using this method, we found that disc geometry was measurable with precision less than the in-plane dimensions of a voxel (≈100⯵m, 10% of the MRI pixel size). Furthermore, there was excellent agreement between mean disc height, disc perimeter, disc volume and regional disc height measurements for multiple trials from an individual rater (standard deviation <3.1% across all measurements) and between mean height, perimeter, and volume measurements made by two independent raters (error <1.5% across all measurements). We then used this measurement system to track diurnal deformations in the L5-S1 disc in a young, healthy population (nâ¯=â¯8; age 24.1⯱â¯3.3 yrs; 2â¯M/6F). We measured decreases in the mean disc height (-8%) and volume (-9%) with no changes in perimeter over an eight-hour workday. We found that the largest height losses occurred in the posterior (-13%) and posterior-lateral (-14%) regions adjacent to the outer annulus fibrosus. Diurnal annulus fibrosus (AF) strains induced by posterior and posterior-lateral height loss may increase the risk for posterior disc herniation or posterior AF tears. These preliminary findings lay a foundation for determining how deviations from normal deformations may contribute to back pain.
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Ritmo Circadiano , Degeneración del Disco Intervertebral/diagnóstico por imagen , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Imagen por Resonancia Magnética , Adulto , Dolor de Espalda , Femenino , Humanos , Disco Intervertebral/diagnóstico por imagen , Masculino , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
Previous study claimed that disc degeneration may be preceded by structure and matrix changes in the intervertebral disc (IVD) which coincide with the loss of distinct notochordally derived nucleus pulposus (NP) cells. However, the fate of notochordal cells and their molecular phenotype change during aging and degeneration in human are still unknown. In this study, a set of novel molecular phenotype markers of notochordal NP cells during aging and degeneration in human IVD tissue were revealed with immunostaining and flow cytometry. Furthermore, the potential of phenotype juvenilization and matrix regeneration of IVD cells in a laminin-rich pseudo-3D culture system were evaluated at day 28 by immunostaining, Safranin O, and type II collagen staining. Immunostaining and flow cytometry demonstrated that transcriptional factor Brachyury T, neuronal-related proteins (brain abundant membrane attached signal protein 1, Basp1; Neurochondrin, Ncdn; Neuropilin, Nrp-1), CD24, and CD221 were expressed only in juvenile human NP tissue, which suggested that these proteins may be served as the notochordal NP cell markers. However, the increased expression of CD54 and CD166 with aging indicated that they might be referenced as the potential biomarker for disc degeneration. In addition, 3D culture maintained most of markers in juvenile NP, and rescued the expression of Basp1, Ncdn, and Nrp 1 that disappeared in adult NP native tissue. These findings provided new insight into molecular profile that may be used to characterize the existence of a unique notochordal NP cells during aging and degeneration in human IVD cells, which will facilitate cell-based therapy for IVD regeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1316-1326, 2016.
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Envejecimiento/metabolismo , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Degeneración del Disco Intervertebral/metabolismo , Núcleo Pulposo/metabolismo , Adolescente , Adulto , Anciano , Envejecimiento/patología , Niño , Colágeno Tipo II/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Núcleo Pulposo/patología , FenotipoRESUMEN
Surgical treatment of complex cervical spinal deformities can be challenging operations. Patients often present with debilitating conditions ranging from generalized decreased quality of life to quadriplegia. Surgical treatment can be divided into anterior, posterior, or combined procedures. A thorough understanding of anatomy, pathology, and treatment options is necessary. This article focuses on the surgical treatment of complex spinal deformity.